Empagliflozin ameliorates ventricular arrhythmias by inhibiting sympathetic remodeling via nerve growth factor/tyrosine kinase receptor A pathway inhibition.

Background and aims: Sodium-glucose cotransporter 2 inhibitors (SGLT2is) can ameliorate arrhythmias; however, the mechanisms underlying their antiarrhythmic effect remain unclear. Therefore, we aimed to test the hypothesis that the SGLT2i empagliflozin (EMPA) ameliorates ventricular arrhythmias caused by myocardial infarction (MI) by inhibiting sympathetic remodeling.

Methods: Male nondiabetic Sprague-Dawley rats were divided into Sham ( n  = 10), MI ( n  = 13), low-EMPA (10 mg/kg/day; n  = 13), and high-EMPA (30 mg/kg/day; n  = 13) groups. Except for the Sham group, MI models were established by ligation of the left anterior descending coronary artery. After 4 weeks, the hearts were removed. Echocardiography, electrical stimulation, hematoxylin-eosin staining and Masson's staining, Western blotting, immunohistochemistry (IHC), and ELISA were performed.

Results: Except for left ventricular posterior wall thickness (LVPWT), EMPA treatment significantly ameliorated the left ventricular anterior wall thickness (LVAWT), interventricular septum thickness (IVST), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), and left ventricular ejection fraction (LVEF) in MI rats; there was no statistical difference between the low-EMPA and high-EMPA groups. The threshold for ventricular fibrillation induction and myocardial fibrosis was significantly ameliorated in EMPA-treated rats, and there was no statistical difference between the high-EMPA and low-EMPA groups. EMPA decreased the expression of nerve growth factor (NGF), tyrosine kinase receptor A (TrkA), tyrosine hydroxylase, and growth-associated protein 43 (GAP43) in the left ventricular infarction margin myocardium of MI rats, especially in the high-EMPA group, with a statistically significant difference between the high-EMPA and low-EMPA groups. High-EMPA significantly decreased noradrenaline (NE) levels in the blood of MI rats; however, there was no statistical difference between the low-EMPA and MI groups.

Conclusion: EMPA ameliorated the occurrence of ventricular arrhythmias in MI rats, which may be related to a reduction in sympathetic activity, inhibition of the NGF/TrkA pathway, inhibition of sympathetic remodeling, and improvement in cardiac function and cardiac structural remodeling.